================================================================== BUG: KASAN: use-after-free in ccid_hc_tx_delete+0xde/0x100 net/dccp/ccid.c:188 Read of size 8 at addr ffff88805b399680 by task syz-fuzzer/7818 CPU: 1 PID: 7818 Comm: syz-fuzzer Not tainted 5.1.0-rc1+ #33 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 ccid_hc_tx_delete+0xde/0x100 net/dccp/ccid.c:188 dccp_sk_destruct+0x3f/0x90 net/dccp/proto.c:181 __sk_destruct+0x55/0x6d0 net/core/sock.c:1699 __rcu_reclaim kernel/rcu/rcu.h:227 [inline] rcu_do_batch kernel/rcu/tree.c:2475 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2788 [inline] rcu_core+0x928/0x1390 kernel/rcu/tree.c:2769 __do_softirq+0x266/0x95a kernel/softirq.c:293 invoke_softirq kernel/softirq.c:374 [inline] irq_exit+0x180/0x1d0 kernel/softirq.c:414 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0033:0x40b5c0 Code: f8 84 01 48 8b 00 48 85 c0 74 04 31 c9 eb 98 48 8d 05 54 40 2a 01 48 89 44 24 40 c6 44 24 48 00 48 8b 6c 24 18 48 83 c4 20 c3 <48> 8b 4c 24 28 48 8b 49 30 48 8b 49 18 48 8b 11 8b 48 0c 48 89 4c RSP: 002b:000000c428427ca0 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: 000000c4202ee300 RBX: 000000c4202ee300 RCX: 0000000000000012 RDX: 0000000000877700 RSI: 0000000000000aaa RDI: 0000000000000000 RBP: 000000c428427cb8 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000009923a2 R11: 0000000000000004 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000013 R15: 0000000000000000 Allocated by task 14499: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_kmalloc mm/kasan/common.c:497 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:505 slab_post_alloc_hook mm/slab.h:436 [inline] slab_alloc mm/slab.c:3392 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3554 ccid_new+0x256/0x3f0 net/dccp/ccid.c:151 dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44 __dccp_feat_activate+0x17a/0x270 net/dccp/feat.c:344 dccp_feat_activate_values+0x33a/0x766 net/dccp/feat.c:1538 dccp_rcv_request_sent_state_process net/dccp/input.c:472 [inline] dccp_rcv_state_process+0x116f/0x1935 net/dccp/input.c:680 dccp_v6_do_rcv+0x269/0xbf0 net/dccp/ipv6.c:641 sk_backlog_rcv include/net/sock.h:937 [inline] __release_sock+0x12e/0x3a0 net/core/sock.c:2413 release_sock+0x59/0x1c0 net/core/sock.c:2929 inet_wait_for_connect net/ipv4/af_inet.c:588 [inline] __inet_stream_connect+0x59f/0xea0 net/ipv4/af_inet.c:680 inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719 __sys_connect+0x266/0x330 net/socket.c:1685 __do_sys_connect net/socket.c:1696 [inline] __se_sys_connect net/socket.c:1693 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1693 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 14500: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3764 ccid_hc_tx_delete+0xc1/0x100 net/dccp/ccid.c:190 dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53 __dccp_feat_activate+0x17a/0x270 net/dccp/feat.c:344 dccp_feat_activate_values+0x33a/0x766 net/dccp/feat.c:1538 dccp_create_openreq_child+0x40c/0x570 net/dccp/minisocks.c:127 dccp_v6_request_recv_sock+0x214/0x1da0 net/dccp/ipv6.c:469 dccp_check_req+0x35c/0x6f0 net/dccp/minisocks.c:196 dccp_v6_rcv+0x6d7/0x191e net/dccp/ipv6.c:747 ip6_protocol_deliver_rcu+0x303/0x16c0 net/ipv6/ip6_input.c:394 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:434 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip6_input+0xe4/0x3f0 net/ipv6/ip6_input.c:443 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x1e7/0x320 net/ipv6/ip6_input.c:76 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ipv6_rcv+0x10e/0x420 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core+0x115/0x1a0 net/core/dev.c:4973 __netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5083 process_backlog+0x206/0x750 net/core/dev.c:5923 napi_poll net/core/dev.c:6346 [inline] net_rx_action+0x4fa/0x1070 net/core/dev.c:6412 __do_softirq+0x266/0x95a kernel/softirq.c:293 The buggy address belongs to the object at ffff88805b399680 which belongs to the cache ccid2_hc_tx_sock of size 1240 The buggy address is located 0 bytes inside of 1240-byte region [ffff88805b399680, ffff88805b399b58) The buggy address belongs to the page: page:ffffea00016ce600 count:1 mapcount:0 mapping:ffff88821602e600 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea00015c8208 ffff88809a933b48 ffff88821602e600 raw: 0000000000000000 ffff88805b398080 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805b399580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805b399600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805b399680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805b399700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805b399780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================